Back to EveryPatent.com
United States Patent | 5,636,948 |
Rexius | June 10, 1997 |
A drill for fiber-filled synthetic plastics has an axially extending body with helical grooves spiraling from a drill point toward a shank end. The grooves define helical lands between them having helical land machining edges. At the point axially tapering land and groove point surfaces converge and land point surfaces with machining edges are radiused to merge gradually with the land surfaces rearward of them. The land machining edges are configured with a negative rake. A plurality of cross notches on the lands extending over an axially extending region of the lands from substantially the axially tapering land point surfaces a predetermined distance toward the shank end are configured to create fiber-snipping crosswise helical cutting edges with a positive rake facing the point.
Inventors: | Rexius; William G. (Hemlock, MI) |
Assignee: | Fullerton Tool Company, Inc. (Saginaw, MI) |
Appl. No.: | 434786 |
Filed: | May 4, 1995 |
Current U.S. Class: | 408/224; 407/54; 407/59; 408/1R; 408/230 |
Intern'l Class: | B23B 051/02 |
Field of Search: | 408/223,224,230,715,1 R 407/53,54,59 |
3147646 | Sep., 1964 | Rawcliffe, Jr. | 408/230. |
3244034 | Apr., 1966 | Severdia | 408/72. |
3443459 | May., 1969 | Mackey et al. | 408/230. |
3667857 | Jun., 1972 | Shaner et al. | 408/230. |
4957397 | Sep., 1990 | Huff | 408/230. |
Foreign Patent Documents | |||
405057517 | Mar., 1993 | JP | 408/230. |
Fluting Specifications, p. 1, Warehouse to the Nation. (Date of publication unknown -- but prior art). Fullerton Tool Catalog 93. (Date of publication unknown -- but prior art). |